I've been using a WD 3TB USB drive for backing up data on my FreeBSD (8.1-release) web server at home. Drive is a single partition in ZFS, the only drive in the pool.

It was working fine this morning, I was copying data to it with no problem. I had a moment to think about it and remembered that while the server itself is on UPS power, the drive is not. So I used umount (should I have used zfs instead?) to unmount the drive, and then attempted to remount it using the zfs command after I reconnected everything.

Code:

web# zfs mount net-backup

Has been running for a very long time (over 15 minutes as of this writing) with no response. The system is responsive, but the command appears to be waiting on something. It doesn't seem to be using a great deal of resources, though I can't kill it with Ctrl-C, 'kill', or even 'kill -9' as root (obviously the zfs command is run as root).

If I do Ctrl-T I see something like:

Code:

load: 0.00 cmd: zfs 14117 [zio->io_cv)] 1492.71r 0.00u 0.00s 0% 1344k

I googled for "zio->io_cv" but haven't found much insightful so far. I'm considering rebooting the system at this point in case something is hung but not reporting correctly?

System is a 2ghz P4 with 1gb ram. It's purpose in life is to serve pages for my home website (which has very little traffic) and to act as a gateway for me to access resources at work and other places (ssh traffic in that case). I know this is a very meager setup for zfs, and I just added the lines to /boot/loader.conf that were suggested in http://wiki.freebsd.org/ZFSTuningGuide

I just noticed something that I should have included in the original message, part of the "zpool status -v" return:

Code:

errors: Permanent errors have been detected in the following files:
<metadata>:<0x0>
<metadata>:<0x14>

However, all the google returns on this seem to be from people having problems with RAID arrays, and I have only one drive.

I then went ahead and rebooted since nothing else seemed to be leading anywhere; any kind of zfs process just hung the way I indicated before. After rebooting I was able to mount the zfs volume without any difficulty; I could read the directories without incident though didn't try many files.

I then started a scrub, which initially stated it would take ~6hrs - now its looking like closer to 3.